Java program to implement Alpha-Beta Pruning (AI)

import java.io.*;

import java.util.*;

class AlphaBeta{

static int MAX = 1000;

static int MIN = -1000;

static int minimax(int depth, int nodeIndex,

Boolean maximizingPlayer,

int values[], int alpha,

int beta)

{

if (depth == 3)

return values[nodeIndex];

if (maximizingPlayer)

{

int best = MIN;

for (int i = 0; i < 2; i++)

{

int val = minimax(depth + 1, nodeIndex * 2 + i,

false, values, alpha, beta);

best = Math.max(best, val);

alpha = Math.max(alpha, best);

if (beta <= alpha)

break;

}

return best;

}

else

{

int best = MAX;

for (int i = 0; i < 2; i++)

{

int val = minimax(depth + 1, nodeIndex * 2 + i,

true, values, alpha, beta);

best = Math.min(best, val);

beta = Math.min(beta, best);

if (beta <= alpha)

break;

}

return best;

}

}

public static void main (String[] args)

{

Scanner sc=new Scanner(System.in);

System.out.println("Enter Length of Element :");

int n = sc.nextInt();

int values[] = new int[n];

System.out.println("Enter Element :");

for(int i=0;i<n;i++){

values[i]=sc.nextInt();

}

System.out.println("The optimal value is : " +

minimax(0, 0, true, values, MIN, MAX));

}

}

Output:

Desktop $ javac AlphaBeta.java

Desktop $ java AlphaBeta

Enter Length of Element :

16

Enter Element :

10

5

7

11

12

8

9

8

5

12

11

12

9

8

7

10

The optimal value is : 8